The present invention relates to an image input device to obtain a three-dimensional image by using a linear sensor.
The following two types of image input devices have been hitherto generally known as an image input device to obtain a two-dimensional image by using a linear sensor. One type is an image scanner which is being remarkably popular at present. The other type is a device in which a linear sensor is disposed on a film face of a silver chloride camera using middle-size or large-size films and then the linear sensor is moved along the film face to obtain a two-dimensional image (hereinafter referred to as “linear sensor scan camera”). As compared with an image input device for obtaining a two-dimensional image by using an area sensor, both the above devices have an advantage that a two-dimensional image of ultra-high resolution can be obtained.
However, in the conventional image input devices, in the case of the former image scanner, the positional relationship between a subject and an image scanner is substantially fixed, and thus there is no degree of freedom in distance between the subject and the image scanner. Further, in the case of the latter linear sensor scanner camera, the severe mechanical precision is required to move the linear sensor, so that it needs much time and effort to manufacture a precise moving mechanism and the cost is increased. In addition, since the speed at which the linear sensor is moved is low, there is such a drawback that it takes much time to input a two-dimensional image.
Accordingly, in any system described above, at present situation it is difficult to convert a three-dimensional space to a two-dimensional image by using a linear sensor. From such a situation,. it is practically difficult to obtain a two-dimensional moving picture by using a linear sensor.
Further, since the linear sensor is designed like a line, the accumulation time of image pickup information of one scan is shorter than that of the area sensor. As a result, even when the subject is exposed to the same light, an image obtained is darker as compared with an image input device using a linear sensor. Accordingly, from this viewpoint, it is difficult to convert the three-dimensional space to the two-dimensional image under such an environment as night or rainy situation which lacks light amount.